#include<stdio.h>
#include<assert.h>
int mystrlen1(char* a)
{
	assert(a);
	int count = 0;
	while (*a)
	{
		count++;
		a++;
	}
	return count;
}
int mystrlen2(char* a)
{
	assert(a);
	char* s1 = a;
	while (*s1)
	{
		s1++;
	}
	return s1 - a;
}
int mystrlen3(char* a)
{
	if (!*a)
	{
		return 0;
	}
	else
	{
		return 1 + mystrlen3(a + 1);
	}
}
int main()
{
	char arr[] = "abcderg";
	int a = mystrlen1(arr);
	int b = mystrlen2(arr);
	int c = mystrlen3(arr);
	printf("%d %d %d", a, b, c);
	return 0;
}